World-wide interests have been focused on AIDS due to its unfavorable prognosis. It is a clinical syndrome known to occur more frequently among the male homosexualists, and is characterized by the clinical syndromes such as pnemocystis carinii pneuomonia, Kaposi's sarcoma, etc. and induces a high mortality of more than 70% by the dysregulation of immune system. It is also known that helper-T cells are specifically destroyed by the infection of the AIDS virus (e.g. HTLV-III).
As a result of the extensive study on the properties of the AIDS viruses, the present inventors have found out the fact that prostaglandins E.sub.2 and D.sub.2 have an action to accelerate, proliferation of AIDS virus (Proc. Natl. Acad. Sci. USA, 83, 3487-3490, May, 1986). In view of this fact, the present inventors have thought of a possibility that the proliferation of AIDS viruses could possibly be inhibited by inhibiting, conversely, the biosynthesis of prostaglandins.
Based on the above thought, the present inventors have conducted an experiment to uncover whether Diclofenac sodium, one of the non-steroidal anti-inflammatory substances, would inhibit proliferation of AIDS viruses. As a result, it has been confirmed that the production of virus is inhibited in vitro when the above substances are incubated with the AIDS virus producing cells. It has also been confirmed that the other non-steroidal anti-inflammatory substances exhibit the similar activities. The present invention has been completed on the basis of such findings.